| 摘要 |
PURPOSE:To know the distance to a target not by the measurement with the eye, by providing a member indicating the distance to the target at a focal position on an index on the basis of the position of a movable part of a focus adjusting device. CONSTITUTION:An indicating member 18 has a number of light-emitting bodies 21 formed of liquid crystal or LED which are provided parallel along scales 19 in a peripheral edge part of a transparent disc. A driver circuit 17 is provided for making the light-emitting bodies 21 in predetermined numbers emit a light according to a resistance value taken from a contact 15, and the correlation between input and output is set therein so that the light-emitting bodies 21 in required numbers including a light- emitting body 21 indicating the maximum distance on a scale 19 to a light-emitting body 21 positioned at a scale corresponding to the distance are made to emit a light when focusing is made on the target by the rotation of a central wheel. When the central wheel is rotated while looking is made through an eye lens, the light-emitting bodies 21 in the number according to an angle of the central wheel emit lights in the visual field of the eye lens. When focusing is made on the target, a scale 19 at a place whereat the forefront one of the plurality of light-emitting bodies 21 emitting lights is positioned is read, and thereby the distance can be known. |
